Orbi-lift positioning device

ABSTRACT

This invention is for a positioning device to position apparatus in different positions, such as a saw assembly in different positions. In a saw mill trimmer there are a number of saws. In the trimming of lumber it is to have some or all of the saws out of contact with the lumber. At other times it is necessary to have some or all of the saws in contact with the lumber. This invention is directed to the positioning of the saws in contact with the lumber and out of contact with the lumber.

United States Patent [n13,589,416

72 Inventors Warren H. Zuercher; 920,726 511909 Candee 192/25 Pierre Juillerat, both of Seattle. Wash. 977,409 1 H1910 Kirk 74/25 [21] Appl. No. 553,747 1,310,018 7/1919 Hoelemann 192/25 [22) Filed May 31, 1966 1606.308 11/1926 Lund 143/46 [45] Patented June 29, 1971 1,627,313 5/1927 Bowe 192/25 [73] Assignee Stetson-Rom Machine Company, Inc. 2,3 24,080 7/1943 Haunty 192/25 Seattle. Wash- FOREIGN PATENTS 539.365 11/1931 Germany 143/46 [54] ORBI-LIFT POSITIONING DEVICE Primary Examiner- Francis S. Husar 7 Claims, 22 Drawing Figs. Artorney-Thomas W. Secrest 521 vs. cl 143/46,

74,25 83/433 83/490 92/25 ABSTRACT: This invention is for a positioning device to posi- [51] Int. Cl B27b 5/00, lion apparatus in different positions, Such as a Saw assembly in Fwd 3/44 different positions. In a saw mill trimmer there are a number Fleld of Search of saws. n e of lumber is to have some or a" of 46-55, 47; 74/25; 192/25, 67; 83/ 490 the saws out of contact with the lumber. At other times it is [56] w References Cited necessary to have some or all of the saws in contact with the lumber. ThlS invention is directed to the positioning of the 1 UNITED STATES PATENTS saws in contact with the lumber and out of contact with the 589,614 9/1897 Polson et al. 74/25 1 b PATENTEU JUHZSISYI 35895416 sum 1 ur 8 Fig.1

ATTORNEY PATENTEU JUN29 I971 Wan g A ATTORNEY PATENTED JUN29|971 3589,4165

SHEET 8 UF 8 7 ixzmzsi ATTOR N EY PATENIED Juuzsls'n 3,589,416

sum 8 BF 8 ATTORNEY ORBI-LIFT POSITIONING DEVICE A saw mill trimmer comprisesa plurality of saw-assemblies. Lumber is fed to these saw assemblies to be trimmed and cut into pieces of lumber of various lengths. The lumber is fed to these saw assemblies by means of chains having lugs. Normally, the saw assemblies are positioned above the cutting table or above the conveyor conveying the lumber. In the cutting of a piece of lumber the appropriate saw or saws are lowered to cut the lumber and then raised. This invention is directed to the combination of the saw assembly and the device for positioning the saw assemblies and also .to the device itself for positioning the saw assembly.

In the lowering of the saw assembly to cut the lumber it is necessary that the lowering of the saw assembly or saw assemblies be timed'so as to cut one particular piece of lumber into pieces of lumber of various lengths. It is essential that the saw assembly be lowered at a particular time appropriate with the movement of the lumber by the chain and lug/The saw assembly or saw assemblies must be rapidly lowered to cut the lumber. Further, after the saw assemblies have cut the lumber then the saw assemblies must be rapidly raised so as to be out of the way and not interfere with the operation of the conveyor.

With this background it is an object of this invention to provide a positioning device which has a positive action in positioning a piece of apparatus; to provide a positioning device which is quick acting in both moving a piece of apparatus from a first position to a second position and from a second position to a first position; to provide a positioning device which is positively timed to the lumber conveyor; to provide a positioning device which is positively timed with the movement of lumber on a conveyor; and, to provide a combination of a saw assembly or saw assemblies with a positioning device or devices which move the saw assembly toward a piece of lumber to be cut; and, also, away from said piece of lumber.

These and other important objects and advantages of the invention will be more particularly brought forth upon reference to the accompanying drawings, the detailed description of the invention and the appended claims.

In the drawings:

FIG. 1 is a side elevational view illustrating the positioning device connecting with a saw assembly, in phantom, and shows the saw assembly in a lowered position and in an elevated position;

FIG. 2, on an enlarged scale, shows the positioning device with the eccentric disc in both a lowered position and an elevated position;

FIG. 3 is a diammetrical cross-sectional view of the positioning device and shows the arrangement of the various in dividual elements ofthe positioning device;

FIG. 4 is a lateral cross-sectional view showing the positioning device with the yoke and said positioning device and yoke being in two different positions;

FIG. 5, on an enlarged scale, shows the eccentric disc of the positioning device in an elevated position and in a lowered position;

FIG. 6, taken on line 6-6 of FIG. 3, illustrates the lower finger of the bearing yoke restraining the movement of the latching key toward the clutch striking plate;

FIG. 7 is a view similar to FIG. 6 but shows the lower finger of the bearing yoke out of contact with the latching key so that the latching key is in contact with the clutch striking plate;

FIG. 8 is a view similar to FIG. 7 and also shows the lower finger of the bearing yoke out of contact with the latching key so that the latching key is in contact with the clutch striking plate;

FIG. 9 is a view looking at the brake plate and the interior of the brake plate; I

FIG. I is a diammetrical cross-sectional view looking at the brake plate;

FIG. 11 is a view looking at the outside surface of the clutch striking plate;

FIG. 12 is a circumferential view looking at the clutch striking plate;

FIG. I3 is a side elevational view looking at the bearing yoke and showing the lower finger and the upper finger;

FIG. 14 is a fragmentary view looking at the leading edge of the lower finger;

FIG. 15 is a fragmentary view looking at the inner edge of the upper finger of the bearing yoke;

FIG. I6 is a view looking down on the latching key and showing the inclined bearing surface;

FIG. 17 is a side elevational view of the latching key;

FIG. 18 is a view looking at the side of the hub latch;

FIG. 19 is a circumferential view looking at the hub latch and the circumferential slot;

FIG. 20 is a side view looking at the eccentric disc;

FIG. 21 is a circumferential view looking at the eccentric disc; and,

FIG. 22 is a side elevational view looking at the drive mechanism for the positioning device.

In the drawings it is seen that there is a positioning device 30. In FIG. 3 it is seen that this positioning device 30 comprises a rotating shaft 32, a clutch striking plate 34, a hub latch 36, a latching key 38, a brake plate 40, a yoke 42, and an eccentric disc 44.

In FIGS. 9 and 10 there is illustrated the brake plate 40 having a generally circumferential configuration. However, it is to be noted that there are two substantially flat portions 46 and 48. It is seen that these flat portions are approximately 120- 140 spaced-apart. The brake plate 40-has a central opening 50 and a hub portion 52. The central part of the brake plate 40 is hollowed or recessed at 54. There is a rim 56. Further, there are four spaced-apart bolt openings or screw openings 58.

In FIGS. 11 and 12 there is the clutch striking plate 34 having a hub 60 t and an integral side rim 62. There. are two spaced-apart radial openings 64 for receiving a bolt for securing the clutch striking plate 34 to the rotating shaft 32 so that the clutch striking plate 34 positively rotates with the rotating shaft 32. The rim portion 62 has a diammetrical inner face 66. In this inner face 66 there is a first slot 68 and a second slot 70. These slots 68 and 70 receive the latching key 38 so that the latching key 38 and the hub latch 36 rotate with the rotation of the clutch striking plate 34.

In FIGS. 13, 14, and 15 there is illustrated the bearing yoke 42. It is seen that the bearing yoke 42 comprises a main body having a lower curved portion 82 and an upper curved portion 84. These two curved portions unite at an end or edge 86. The lower curved portion 82 extends into a finger 88. The upper curved portion 84 extends into a finger 90. The inner surface of the finger 88 is curved at 92 and the inner surface of the finger is curved at 94. Then, the innermost portion of the curve 94 of the finger 90 extends upwardly toward the curved portion 84 to form a leading edge 96. Then, the curved surface 92 and the leading edge 96 form the inner curve surface 98 of the yoke 42. In effect, it is seen that the bearing yoke 42 comprisesa main base portion 80 which has two outwardly extending fingers 88 and 90.

In FIG. 14 it is seen that the outer portion of a finger 88 is recessed or cut back to form a sloping surface 100. Further, in FIG. 15 it is seen that the leading edge 96 of the finger 90 is recessed or cut back to form a sloping surface 102.

The reason for the sloping surface 100 on the finger 88 and the sloping surface 102 on the finger 90 is to move the latching key away from the clutch striking plate. This will become more apparent upon further description of the various components of the positioning device and also with reference to the complete assembled drawing of the positioning device.

In FIGS. 16 and 17 there is illustrated a latching key 38. It is seen that the latching key is an elongated piece of metal having in a lateral cross-sectional view a generally rectangular configuration of substantially four flat sides. In one end there is drilled an opening or a passageway 110. This passageway is to receive a spring so that the latching key is spring loaded. Above the passageway 110 and slightly offset from the lateral center axis of the latching key 38 there is a slot 112.

The side of the slot 112 is recessed at 114 so as to have a sloping edge or bearing surface 114. Then, the bearing surface 114 meets with the side 116 of the slot 112. Then, the side 116 extends into a tapered or chamfered edge 118. The slot 112 receives one of the fingers 88 or 90 of the bearing yoke 42. The sloping surface 114 is a guide surface so as to assist in guiding the finger 88 or the finger 90 into the slot 112.

In FIGS. 18 and 19 there is illustrated the hub latch 36. In FIG. 18 it is seen that the hub latch 36 is in the configuration of a torus and has a central opening 120 and an exterior surface 122. In the exterior surface 122 there is a longitudinal slot 124. The longitudinal slot 124 receives the latching key 38. Therefore, the interior dimensions of the longitudinal slot 124 is slightly larger than the exterior dimensions of the latching key 38. Further, in the circumferential surface 122 of the hub latch 36 there is a circumferential slot or groove 126. The circumferential slot or groove 126 is to receive a finger 88 or a finger 90 of the bearing yoke 42. Further, it is seen that in the exterior surface 122 of the hub latch 36 that there are four tapped passageways or openings 128. These openings 128 receive setscrews from the eccentric disc so as to position the eccentric disc 44 onto the hub latch 36.

In FIGS. and 21 there is illustrated the eccentric disc 44. It is seen that the eccentric disc 44 comprises a hub portion 130 which has an opening 132. On the hub portion 130 there is positioned a disc 134. However. the disc 134 is not so positioned that the disc 134 is concentric with the hub 130. The center of the disc 134 is offcenter from the center of the hub 130 so that the disc 134 becomes an eccentric disc 134. The disc 134 has a central opening 136. The opening 136 is slightly larger in internal diameter than the external diameter of hub 130 so that the disc I34 fits over the hub 130. The disc 134 is welded to the hub 130. Further, it is seen that in the hub 130 that there are four passageways 138 for receiving setscrews for positioning the eccentric disc 44 onto the hub latch 36.

The outer rim or sides of the eccentric disc 134 are cut back or recessed at 140 so as to have a shoulder 142.

The positioning device is assembled and mounted as follows. In FIGS. 3 and 4 it is seen that there is a mounting base 150. This mounting base comprises a bearing block 152. A bearing 154 is mounted on the bearing block 152 by means of bolts 156. The shaft 32 is journaled in the bearing 154. As is seen in FIG. 3 there is mounted on the shaft 32 the clutch striking plate 34. In the shaft 32 there are two drilled recesses 158. Setscrew 160 is screwed into the tapped opening 64 in the clutch striking plate 34 so that the end is set into the recesses 158 so as to definitely position the clutch striking plate 34 onto the shaft 32. Then, there is a bushing 162 around the shaft 32, and to the right of the clutch striking plate 34. The hub latch 36 is positioned around the bushing 162. The latching key 38 is placed in the slot 124 of the hub latch 36. In the recess 110 of the latching key 38 there is a spring 164. The latching key 38 and the spring 164 are so placed in the slot 124 that the latching key 38 is urged towards the clutch striking plate 34. The eccentric disc 44 is then placed on the outside of the hub latch 36 so that the opening 132 of the eccentric disc 44 overlaps slightly the rim 62 of the clutch striking plate 34. The eccentric disc 44 is positioned on the hub latch 36 by means of screws or bolts 166 screwed through the openings 138 in the hub 130 of the hub latch 36 and into the tapped openings 128 of the hub latch 36. In this manner the eccentric disc 44 rotates with the rotation of the hub latch 36. Then, the brake plate 40 is positioned on the hub latch 36 and attached to the hub latch 36 by means of bolts 167 passing through the passageways 158 in the brake plate. In FIG. 9 it is seen that there are four passageways 58. In the hub latch 36 there are four tapped passageways 168, see FIG. 18, on the diammetrical surface of the hub latch 36 and which tapped passageways 168 receive the bolts 166. In this manner the brake plate 40 rotates with the rotation of the hub latch 36. Then, a steel collar 170 is positioned on the shaft 32 and adjacent to the brake plate 40 so as to definitely position the brake plate 40 on the shaft 32. The collar 170 is set by a setscrew 172 in a tapped passageway in the collar 170. Further, there is the bearing yoke 42. This bearing yoke is so mounted that the upper finger is above the shaft 32 and between the hub of the eccentric disc 44 and the rim 56 of the brake plate 40, as is illustrated in FIG. 3. Also, the lower finger 88 of the bearing yoke 42 is below the shaft 32 and adjacent to the latching key 38. In FIG. 13 it is seen that the bearing yoke 42 has a passageway or opening 174 near the edge 86 of the base 80 and also a second opening 176 in the lower part of the base 80 and near the finger 88. The opening 176 receives a pivot pin. In FIG. 4 it is seen that the bearing block 152 has a tapped passageway 178 on one face. There is a collar 180 welded to the bearing block 152. The bearing yoke 42 abuts against the outside surface of the collar 180 and pivots around the pivot pin 182 which passes through the pivot opening 176. In this manner the bearing yoke 42 is positioned so that the upper finger and the lower finger are in the positioning device 30.

The base 150 has an upright pedestal 190. The upper part of the pedestal supports a ledge 192. Mounted on the rear of the ledge 192 is a solenoid 194. In the rear part of the ledge 192 there is an opening or passageway 196. The solenoid 194 has a downwardly extending plunger 198 which extends through the passageway or opening 196. The plunger 198 connects with a pushrod 200. The lower end of the pushrod 200 connects with a connector 202. The connector 202 connects with a pin 204 in the opening 174 in the bearing yoke 42. In the pedestal 190 it is seen that there is a ledge 206 approximately half way up the pedestal 190. In the ledge 206 there is an opening 208. A spring 210 is around the pushrod 200 and bears against a nut 212 on the upper end of the pushrod 200 and also against the ledge 206 so as to urge the pushrod 200 and the plunger 198 upwardly.

On the front or forepart of the pedestal, there is a brake 220. There is a plunger 222 which connects with a brakeshoe 224. On the pedestal 192 there is a base 226 which connects with an upper ledge 228. The plunger is threaded at approximately its midsection. There are nuts 232 threaded onto the plunger. A spring 230 encircles the plunger 222 and bears against the base 226 and the ledge 228. By adjusting the nuts 232 it is possible to permanently position the brakeshoe 224. With the brakeshoe permanently positioned, the brake slows the downward movement of the hub latch 34 and the latching key 38 as the brakeshoe 224 is in contact with the lobe 45 on the brake plate 40. On the upward movement the brakeshoe 224 is not in contact with the recessed surface 47.

In the positioning device 30, the eccentric disc 44 is moved or rotated so that the disc portion 134 presents a small distance between the center of the hub 130 and the perimeter disc portion 134 or presents a large distance between the center of the hub 130 and the perimeter of the disc portion 134. In this manner it is possible, with other means, to move a piece of apparatus.

The movement of the eccentric disc 44 is accomplished by rotating the eccentric disc 44. In FIG. 3 the shaft 32 is constantly rotated. As is recalled the clutch striking plate is keyed or set to the shaft 32 so as to constantly rotate with the rotation of the shaft 32. The eccentric disc 44, the brake plate 40 and the latching key 38 may rotate with rotation of the clutch striking plate 34 or may not rotate with the rotation of the clutch striking plate 34. In FIG. 3 the lower finger 88 of the bearing yoke 42 is in the slot 112 of the latching key 38. This means that the latching key 38 is out of contact or not in contact with the clutch striking plate 34, i.e., the latching key 38 is not in the slot 68 or the slot 70 on the face of the clutch striking plate 34.

In this position the bearing yoke 42 is rotated upwardly as the solenoid 194 is energized so as to move the plunger 198 and the pushrod 200 downwardly so as to rotate the bearing yoke 42, see FIG. 4, in a counterclockwise direction. As is seen in FIG. 3 the distance between the center of the eccentric disc 44 and the perimeter of the eccentric disc 134 is the least distance with respect to the upper part of the eccentric disc 134 on the eccentric disc 44. Now, in order to rotate the eccentric disc 44 so that the distance. at the upper part or above the shaft 32 is greatest between the center of the hub 130 and the outer perimeter 134 of the eccentric disc, it is necessary to deenergize the solenoid 194. The spring 210 urges the pushrod 200 and the plunger I98 upwardly so as to urge the bearing yoke 42, see FIG. 4, in a clockwise direction. With this rotation of the bearing yoke 42 in a clockwise direction, the finger 94 and also the inner inclined surface 102 move downwardly and the finger 88 moves out of contact with the latching key 38. With the finger 88 out of contact with the latching key 38, the spring 164 contacts the clutch striking plate 34 so as to move into a slot 70 or a slot 68. With the rotation of the shaft 32 and the clutch striking plate 34, the latching key 38 also rotates and with it rotates the hub latch 36 and eccentric disc 44. However, with the rotation of the latching key 38, and the downward position of the finger 90. the inclined surface 102 of the finger 90 contacts the inclined surface 114 of the latching key 38 when the two are positioned adjacent to each other and the latching key 38 is moved to the right so as to be out of contact with the clutch striking plate 34 and also out of contact with the slot 68 and the slot 70. Then, the latching key 38, the hub latch 36, and the eccentric disc 44 cease to rotate. At this time the distance between the center of the hub 130 of the hub latch 36 and the perimeter of the eccentric disc 134 is greatest when the eccentric disc 134 is positioned substantially directly above the shaft 32.

In FIG. 6 there is illustrated the position of the lower finger 88 in contact with the slot 112 of the latching key 38. This is also seen in FIG. 3 and it is seen that the latching key 38 is not in contact with the clutch striking plate 34.

In FIG. 7 it is seen that the lower finger 88 has been moved out of the slot 112 of the latching key 38 and that the spring 164 has urged the latching key 38 toward the clutch striking plate 34 so that the clutch striking plate 34, the hub latch and the eccentric disc 44 are keyed together.

In FIG. 8 it is seen that the latching key 38 is in contact with the clutchstriking plate 34 and that the inclined edge 100 of the lower finger 88 is about to contact the surface 114 of the latching key 38 and also move into the slot 1 12 of the latching key 38. From previous explanation it is seen that the latching key 38 will be moved out of contact with the clutch striking plate 34 and that the clutch striking plate 34 and the hub latch 36will not be keyed.

A practical application of the use of the positioning device 30 is illustrated in FIG. 1 and FIG. 2. In these figures it is seen that the mounting block 150 is mounted on a table 250 by means of bolts 252. Also, see FIG. 3, there is mounted a tiedown unit 254 on the table 250. The tie-down unit 254 comprises two bearing members 256. A rod 258 is journaled in the bearing members 256. On one end of the rod, the left end in FIG. 3, there is a ledge 260. A pin 262 connects a chain 264 to the ledge 260. The chain 264 passes around the eccentric disc 44 or passes around the peripheral portion of the disc 134. It is seen that the outer portion of the disc 134 is recessed at 140 to provide a step 142. The recessed portion 140 and the step portion 142 act as a guide for the links of the chain 264. The lower end of the chain 264 connects with the tie buckle 266. The tie buckle 266 connects with a connector 268. The connector 268 connects with a saw assembly 270. On the saw assembly 270 there is an adapter 272 having three openings 274, 276, and 278. With these three openings it is possible to have three different throws of the saw assembly 270. The adapter 272 is attached to an arm 280. The arm 280 is pivoted arotlnd pivot pin or bolt 282. The bolt 282 connects with a base or mount 284. The teeth of the saw 286 are illustrated. The reference numeral'288 refers to the lower position of the saw assembly 270 and the reference numeral 290 refers to the elevated position of the saw assembly 270.

It is seen that by the rotation of the eccentric disc 44 and the disc 134 that the saw assembly may be quickly elevated from the lower position 288 to the upper position 290, or it may be lowered from the elevated position 290 to the lower position 288. This is clearly brought forth with reference to FIG. 5. It is seen in FIG. 5 that with the eccentric disc 44 as shown in the solid line that the saw assembly 270 is in the lowered position 288 (for illustrative purposes the reference numeral 288 is shown in conjunction with the solid line eccentric disc 44, FIG. 5). In FIG. 5 it is seen that in the solid line eccentric disc 44 the distance between the center of the shaft 32 and the upper part of the disc 44 is a minimum. When the eccentric disc 44 is rotated approximately I, the saw assembly 270 is elevated to the elevated position 290 (for purposes of illustration, the reference numeral 290 is applied to the broken line eccentric disc in FIG. 5). In FIG. 5 it is seen that the distance between the center of the shaft 32 and the top of the chain 264 on the eccentric disc 44 is a maximum so as to have the saw assembly 270 in the elevated position.

By way of recapitulation, the rotation of the eccentric disc 44 is readily and easily accomplished by means of the constantly rotating shaft 32 and the clutch striking plate 34. The hub latch 36 and the eccentric disc 44 are caused to rotate by the interlocking of the latching key 38 with the clutch striking plate 34 and, are taken out of rotation by removing the latching key 38 from the clutch striking plate 34. I

In the slowing down of the downward movement of the saw assembly 270, as can be readily appreciated, the weight of the saw assembly 270 tends to pull down the brake plate 40, the eccentric disc 44 and the latching key 38. The latching key 38 bears against the hub 36 so as to tend to pull down or rotate the shaft 32 in a downward direction. From experience it has been found that it is desirable that the hub latch 36 bear against the latching key 38 so as to drive the latching key 38 instead of the latching key 38 driving the hub latch 36. Therefore, the brake plate 40 has the lobe 45 so that in the downward movement of the saw assembly 270, the brakeshoe 224 contacts the lobe 45 so as to slow down the downward movement of the saw assembly 270. As a result the hub latch 36 drives the latching key 38. On the upward movement of the saw assembly 270, it is not necessary to have the brakeshoe 224 contact the brake plate 40. Therefore, the brake plate 40 is recessed at 47 so that the brakeshoe 224 does not contact the brake plate 40. In this manner it is possible to set the position of the brakeshoe 224 so that this brakeshoe is at only one position. Then, with the downward movement of the saw assembly 270, the brakeshoe contacts the brake plate 40, and with the upward movement of the saw assembly 270, the brakeshoe 224 is not in contact with the brake plate 40.

In a trimmer there is not usually used one saw assembly alone. There are used a plurality of saw assemblies. For example, depending upon the size of the trimmer, there may be used 10 or 20 saw assemblies. Therefore, it is necessary to have a corresponding number of positioning devices 30. Further, the constantly rotating shaft 32 for all of these saw assemblies is generally not one continuous shaft. It is a series of short shafts 32 connected by union or couple 300. Therefore, it is possible to easily replace a positioning device 30 by merely removing the couple or union 300 and inserting another positioning device.

As previously stated, the raising and lowering of the saw assembly 270 is in timed relation with the continuous variable movement of a conveyor. The conveyor moves a piece of lumber into position to be sawed. It is necessary for the saw assembly to be lowered to saw this piece of lumber. After the piece of lumber has been sawed, then it is necessary to elevate or raise the saw assembly so as not to be in the way of the next piece of lumber. In this regard, it is necessary to have a timed relationship between the conveyor for moving the piece of lumber and, also, the movement of the positioning device 30. In FIG. 22 there is illustrated the table 250. On the table 250 there is a base 301. It is seen that there is a bearing block 302. A bearing 304 is mounted on the bearing block 302 by means of bolts 306. In the bearing 304 there is the constantly rotating shaft 32. Also, mounted on the bearing base 300, are two other bearing blocks. These bearing blocks are mounted at a lower elevation than the bearing block 304. It is seen that there is a bearing block 308 mounted on the base 301 by means of bolts 310, and a bearing block 312 mounted on a base 301 by means of bolts 314. The bearing block 308 journals a shaft 316. On the shaft 316 there is mounted a sprocket 318. The bearing 312 journals a shaft 320. On the shaft 320 there is mounted a sprocket 322. Below the table 250, there is the head shaft 324 of the trimmer. The head shaft 324 carries a sprocket 326. A chain 327 wraps around the sprocket 326, a sprocket 328 mounted on the shaft 32, the sprockets 322 and 318. It is seen that the sprocket 326 in a driving relationship with sprocket 328 so as to drive the constantly rotating shaft 32. The sprockets 318 and 322 may be considered to be idler sprockets and sprockets for taking up the tension in the chain 327. Also, there is mounted on the shaft 324 a sprocket 330. A chain 332 runs around the sprocket 330. The chain 332 carries lugs 334. As is illustrated in FIG. 22, the lugs 334 push a piece of lumber 336 forward so as to be in position to be cut by the saw assembly 270. In this manner, by having the head shaft 324 to drive the chain 332 with the lugs for moving the lumber and the rotating shaft 32 for driving the positioning device 30, it is seen that there is a timed relation between the movement of the chain 332 carrying the lug 334 and the movement of the positioning device 30. This is essential as the saw assembly 270 must be moved upwardly after it has performed its function of sawing the piece of lumber 336. Also, it is essential that the saw assembly 270 must be quickly moved downwardly to saw the piece oflumber 336.

From the foregoing it is seen that we have provided a positioning device which quickly moves a piece of apparatus from one position to another position in timed relation with the movement of another device such as a conveyor.

Having presented our invention, what we claim is:

l. A positioning apparatus, said apparatus comprising:

a. a shaft;

b. a clutch striking plate;

c. said plate connecting with said shaft for continuously rotating with said shaft;

d. said plate on its inner face having a first slot;

e. a hub latch on said shaft;

f. a second slot in said hub latch;

g. said inner face facing said hub latch;

h. a latching key in said second slot;

i. a first means urging said key towards the inner face of the plate;

j. a second means for moving said key out of the first slot and away from said inner face;

k. a brake plate connecting with said hub latch;

I. an eccentric mounted on said hub latch; and,

m. a flexible means running around said eccentric and connecting with a third means to be moved.

2. A positioning apparatus according to claim 1 and comprising:

a. said plate on its inner face having a plurality of first slots;

b. said second means comprising a yoke having a first finger and a second finger;

c. said first finger being adapted to move said key out of one of said first slots and away from said inner face; and,

d. said second finger being adapted to move said key out of one of said first slots and away from said inner face.

3. A combination of a saw assembly and an apparatus for positioning the saw assembly, said combination comprising:

a. said saw assembly;

b. a clutch striking plate;

c. a hub latch;

d. a latching key;

e. a first means to move the latching key to connect and to disconnect the clutch striking plate and the hub latch;

f. a second means connecting with the hub latch and comprising an eccentric; and,

g. a flexible means running around said eccentric and connecting with said assembly.

4. A combination of a saw assembly and an apparatus for positioning the saw assembly, said combination comprising:

a. said saw assembly; b. a sha c. a clutch striking plate;

d. said plate connecting with said shaft;

e. said plate on its inner face having a first slot;

f. a hub latch on said shaft;

g. a second slot in said hub latch;

h. said inner face facing said hub latch;

i. a latching key in said second slot;

j. a first means urging said key towards the inner face of the plate;

k. a second means for moving said key out of the first slot and away from said inner face;

I. a brake plate connecting with said hub latch;

m. an eccentric mounted on said hub latch; and,

n. a flexible means running around said eccentric and connecting with said saw assembly.

5. A combination according to claim 4 and comprising:

a. said plate on its inner face having a plurality of first slots;

and

b. said saw assembly being below said eccentric and adapted to move with the rotation of the eccentric.

6. A combination according to claim 5 and comprising:

a. said plurality ofslot being two slots; and

b. said two slots being spaced approximately apart so that the hub latch and the clutch striking plate are engaged and disengaged at about 180 intervals.

7. A combination according to claim 4 and comprising:

a. a plurality of said combinations of said saw assembly and said apparatus; and,

b. said rotating shaft being common to all apparatus. 

1. A positioning apparatus, said apparatus comprising: a. a shaft; b. a clutch striking plate; c. said plate connecting with said shaft for continuously rotating with said shaft; d. said plate on its inner face having a first slot; e. a hub latch on said shaft; f. a second slot in said hub latch; g. said inner face facing said hub latch; h. a latching key in said second slot; i. a first means urging said key towards the inner face of the plate; j. a second means for moving said key out of the first slot and away from said inner face; k. a brake plate connecting with said hub latch; l. an eccentric mounted on said hub latch; and, m. a flexible means running around said eccentric and connecting with a third means to be moved.
 2. A positioning apparatus according to claim 1 and comprising: a. said plate on its inner face having a plurality of first slots; b. said second means comprising a yoke having a first finger and a second finger; c. said first finger being adapted to move said key out of one of said first slots and away from said inner face; and, d. said second finger being adapted to move said key out of one of said first slots and away from said inner face.
 3. A combination of a saw assembly and an apparatus for positioning the saw assembly, said combination comprising: a. said saw assembly; b. a clutch striking plate; c. a hub latch; d. a latching key; e. a first means to move the latching key to connect and to disconnect the clutch striking plate and the hub latch; f. a second means connecting with the hub latch and comprising an eccentric; and, g. a flexible means running around said eccentric and connecting with said assembly.
 4. A combination of a saw assembly and an apparatus for positioning the saw assembly, said combination comprising: a. said saw assembly; b. a shaft; c. a clutch striking plate; d. said plate connecting with said shaft; e. said plate on its inner face having a first slot; f. a hub latch on said shaft; g. a second slot in said hub latch; h. said inner face facing said hub latch; i. a latching key in said second slot; j. a first means urging said key towards the inner face of the plate; k. a second means for moving said key out of the first slot and away from said inner face; l. a brake plate connecting with said hub latch; m. an eccentric mounted on said hub latch; and, n. a flexible means running around said eccentric and connecting with said saw assembly.
 5. A combination according to claim 4 and comprising: a. said plate on its inner face having a plurality of first slots; and b. said saw assembly being below said eccentric and adapted to move with the rotation of the eccentric.
 6. A combination according to claim 5 And comprising: a. said plurality of slot being two slots; and b. said two slots being spaced approximately 180* apart so that the hub latch and the clutch striking plate are engaged and disengaged at about 180* intervals.
 7. A combination according to claim 4 and comprising: a. a plurality of said combinations of said saw assembly and said apparatus; and, b. said rotating shaft being common to all apparatus. 